Apparatus for pumping and separating liquid and gaseous fluids



1 w t n w 7 h 6 m 3 h s G 2 N I T A R A P mw Hm A AG 3, 1966 B. H. MOSBAPPARATUS FOR PUMPIN LIQUID AND GASEOUS FLUIDS Flled March 16. 1964 71MMY @202 3, 1966 B. H. MOSBACHER 3,2 7,

APPARATUS FOR PUMPING AND SEPARATING LIQUID AND GASEOUS FLUIDS FlledMarch 16. 1964 2 Sheets-Sheet 2 75y 5' W WV? 3 267 862 APPARATUS FOR PUMPI NG AND SEPARATING LIQUID AND GASEOUS FLUIDS Bruce H. Mosbacher,Rockford, IlL, assignor to Roper Industries, Inc, Rockford, 111., acorporation of Illinois Filed Mar. 16, 1964, Ser. No. 352,067 14 Claims.((11. 103-6) This application a continuation-in-part of my copendingapplication Serial No. 862,693, filed August 10, 1959, now Patent No.3,137,234.

This invention relates to a pumping apparatus, and particularly to apositive displacement type pumping ap paratus for separating fluidshaving different densities.

An important object of this invention is to provide an apparatus forseparating fluids having different densities and-which will draw thefluids into the apparatus and deliver the same under pressure toeliminate the necessity of auxiliary pumping apparatus for feeding andWithdrawing fluid from the separator.

A more particular object of this invention is to provide a rotarypositive displacement pumping apparatus having a plurality ofcompartments which rotate to centrifugally separate the fluid thereinand which compartments progressively increase in volume in one sector ofthe pump to draw fluid into the chambers and progressively decrease involume in another sector to discharge the fluid under pressure, and inwhich the delivery ports are arranged to receive the centrifugal-1yseparated fluids to deliver the same in different streams.

Another object of this invention is to provide a pumping apparatus whichwill separate gas and vapor from a liquid and discharge the same inseparated streams to return the vapor to the supply reservoir anddeliver the substantially vapor-free liquid to the point of use.

Still another object of this invention is to provide a positivedisplacement type pump apparatus having internal and external meshinggears and a plurality of outlets for discharging fluid in separatestreams, and which pump apparatus has an improved arrangement forrelieving trapped fluid as the tooth spaces move out of communicationwith one outlet port and into communication with another outlet port.

An important feature of the present invention resides in the provisionof a rotary positive displacement type pumping apparatus having aplurality of segregated pumping compartments which expand during oneportion of each revolution to draw fluid into the compartments and whichcontract during a different portion of each revolution and in which .airand gas is vented from the inner periphery of the compartments beforethe liquid is discharged from the compartments.

These, together with various ancillary objects and advantages of thisinvention will be more readily appreciated as the same becomes betterunderstood by reference to the following detailed description when takenin connection with the accompanying drawings herein:

FIGURE 1 is a diagrammatic view of an apparatus for separating fluidshaving different densities, which apparatus employs an internal gearpump and with the gear pump broken away and shown in section along theline 1-1 of FIG. 2 to illustrate details of construction;

FIG. 2 is a sectional view taken on the plane 2--2 of FIG. 1;

FIG. 3 is a sectional view through the pump taken along the plane 3-3 ofFIG. 1;

FIG. 4 is a diagrammatic view of a modified form of apparatus forseparating fluids having different densities, which apparatus employs avane type pump, with the pump broken away and shown in section along theline 4-4 of FIG. 5;

FIG. 5 is a sectional view taken on the plane 5-5 of FIG. 4; and

United States Patent 0 "ice 3,267,862 Patented August 23, 1966 FIG. 6 isa sectional view taken on the plane 66 of FIG. 4;

In general, the apparatus for separating fluids having differentdensities includes a rotary positive displacement pump device, such as agerotor type pump or a vane type pump. Such rotary pumps define aplurality of rotating compartments which progressively increase involume to draw fluid into the compartments and then progressivelydecrease in Volume to discharge the fluid under pressure from thecompartments. It has been found that the rotation of the fluid in thecompartments of such pumps will produce a centrifugal separation of thefluids in the compartments with the heavier fluids lying adjacent theouter periphery of the compartments and the lighter fluids disposedadjacent the inner periphery of the compartments. -In accordance withthe present invention, separate delivery ports are provided and arrangedto receive the centrifu gally separated fluids and deliver the same inseparate streams.

The fluid separating apparatus is generally adapted for use inseparating fluids having different densities and may be used to separatedifferent liquids such as oil and water which have different densities,and also for separating liquids from gases. While the device is hereinillustrated as used to separate two different fluids, the apparatus canbe modified by the provision of additional ports, suitably arranged, toseparate more than two fluids.

Reference is now made more specifically ot FIGS. 1-3 of the drawingswherein there is illustrated an internal gear pump including a housing10 and having outer and inner gerotors 111 and 12 therein defining apumping chamber 18 therebetween. The housing 10 is herein illustrated asbeing formed in a plurality of separate sections including an end wall13, a port plate 14, an annular side wall 15 and an end wall 16. Theaforementioned sections are assembled one on topof the other andretained together by fasteners 17 and, when assembled, define the pumpchamber 18 therein between the end Wall 1 6 and the port plate 14.

The outer rotor 11 is in the form of a ring gear and is rotatablyreceived in the chamber 18 for rotation about the axis thereof. Theinner rotor 12 is disposed within the outer rotor and is mounted forrotation about an axis eccentric to the axis of the outer rotor. Asherein illustrated, the inner rotor 12 is mounted on a shaft 21 and isnon-rotatably connected thereto as by a key 22. Seals 23 and 24 areprovided on the end plates 13 and 16 to prevent leakage of fluid therebyalong the shaft 21. As is conventional, the shaft 21 is connected to asuitable source of power to rotate the inner gear or rotor 12.

The outer rotor 11 has inwardly extending lobes or teeth 27 which meshwith outwardly extending lobes or teeth 28 on the inner rotor 12. In theigerotor type pump shown in FIGURE 1, the lobes 27 and 28 areshaped sothat each of the outwardly extending lobes 28 on the inner rotor isdisposed, in all operative positions thereof, in close running fit withone Of the inwardly extending lobes or teeth 27 on the outer rotor toform a running seal therebetween and separate the pump chamber into aplurality of compartments which rotate with the inner rotor. As theinner rotor 12 .isrotated by the shaft 21, the compartments between theinner and outer rotors in one sector of the pump chamber 18 expand andincrease in volume and the compartments between the inner and outerrotors at the other sector of the pump chamber 18 decrease in volume.When the inner rotor is rotated in a counterclockwise direction asindicated by the arrow in FIGURE 1, the compartments at the right handside of a plane through the axes of the inner and outer rotors areexpanding and the compartments at the left hand side of that plane aredecreasing in volume. Liquid is sup- 'inner and outer rotors.

referred to as a minimum distance. gear type pump ilustrated in FIGS.13, the outer edge inlet port is dimensioned to communicate with thecompartments at the first sector of the chamber, that is, at the inletside of the pump, to supply fluid thereto, but terminates short of theplane through the axes of the inner and outer rotors. The fluid enteringthe pumping chamber through the inlet port 34 is rotated with the Whenthe liquid contains occluded gas or vapor, the relatively light gas willbe centrifugal ly separated from the denser liquid, the denser liquidflowing outwardly into the tooth spaces in the outer rotor 11 and therelatively light vapor and gas being vforced inwardly into theintertooth spaces of the inner rotor. One outlet port designated 38 isprovided for discharging the gas and vapor and one or more other outletports, herein designated 39 and 40 are provided for discharging thesubstantially vapor tree liquid in streams separated from the streamfrom the gas outlet port 38.

In accordance with the present invention, the first outlet port 38 isdisposed at that sector of the chamber at which the compartmentsdiminish in volume, that is, at the side of the plane through the axesof the inner and 'outer rotors opposite the inlet port 34. The discharge.7 port 38 has one end 38a angularly spaced in the direction of rotationof the gears from the inlet port a distance approximately equal to thespacing between the seal points of adjacent teeth on the inner rotorwith the teeth on the outer rotor to prevent direct communicationbetween compartments when the compartments move out of commun-icationwith the first discharge port. This discharge .port is shaped andarranged to communicate with the 4 pockets at the discharge side of thepump in a zone adjacent the roots of the teeth in the inner rotor 12 andspaced radially inward of the roots of the teeth in the outer rotor 11so that the gas and vapor which has collected adjacent the roots of theteeth in the inner rotor 12 will be forced outwardly through thedischarge port 38 as the compartments progressively decrease in volumeduring rotation of the inner and outer rotors. The radially .outer edge380 of the port 38 at the end 38b thereof is arranged to approximatelymerge with the inner periphery of the compartments, that is with theroots of the teeth on the inner gear 12, and the radially outer edge 38cat all other points therealong is spaced from the outer periphery of thecompartments a distance such that the -volume of liquid in thecompartments between the radially outer edge 38c and the outer peripheryof the compart- -ments is no less the volume of liquid that remains inthe compartments when they move out of communication with the port 38.This distance is hereinafter sometimes Thus, in the internal 380 at theend 38b of the port is spaced radially inwardly from the roots of theteeth in the outer rotor a distance approximately equal to the radialspacing between the roots of the teeth in the outer rotor and the rootsof the teeth in the inner rotor when they are adjacent the end 38b .Ofthe port.

In practice, the outer edge 380 at the end 38b of the port should bejust slightly outward from the roots of the teeth on the inner rotor toreceive substantially only the gaseous fluid at the inner periphery ofthe comport. In the embodiment shown in FIG. 1, the outer edge 380 atother points therealong is spaced somewhat farther from the roots of theinner rotor, but is yet spaced inwardly from the roots of the teeth inthe outer rotor a distance at least equal to the aforedescribed minimumdistance which should be maintained between the outer edge 38c and theroots of the teeth on :the outer rotor. However, the outer edge 380, atpoints spaced from the end 38b, can, if desired, be located somewhatcloser to the roots of the teeth in the inner gear than thatspecifically shown in the drawings, if care is taken to provide adequateflow area to prevent excessive restriction of flow from the compartmentsthrough the first outlet port. For example, the outer edge 380 could bemade to extend generally concentric With the axis of the inner rotor, ata radius slightly larger than the radius to the roots of the teeth onthe inner rotor. The location of the inner edge 38d of the rotor is notcritical, so long as it is located radically inwardly of the roots ofthe teeth on the inner rotor and spaced from the shaft suflicient topermit sealing of the end faces of the inner gear.

The relatively dense liquid is centrifugally forced outwardly andremains in the intertooth spaces in the outer rotor 11. This liquid isdischarged separate from the air, may, for example, be dischargedthrough plural ports des ignated 39 and 40. The discharge port 39 isangularly spaced in the direction of rotation of the gears from thedischarge port 38 and, similarly, the port 40 is angularly spaced fromthe port 39. The angular spacing between the discharge ports 38, 39 and40 must be accurately controlled in order to maintain the normally highefliciency of a pump of this type without causing high losses due totrapping of liquid in the space between ports 38, 39 and 40. Moreparticularly, the discharge ports 38, 39 and 40 must be spaced apart adistance suflicient to substantially prevent each pumping compartmentfrom communicating simultaneously with two adjacent ports. As shown inFIG. 1, the second discharge port 39 has one end 39a arranged to extendcrosswise of the compartments as they move therepast and which end isangularly spaced from the end 38b of the first outlet port a distancesuch the seal point designated S between the inner and outer gear teethat the lead side of the pump compartment just moves across the edge 39aat about the time that pump compartment moves out of communication withthe first outlet port. As the seal point S moves across the end 39a, thecompartments begin to discharge into the second outlet port. However,the flow area to the second port is small until the seal point has movedsubstantially past the end 39a. In order to reduce trapping, trappingrelief groove portions designated 39b and 390 are provided at the end3901 and extend toward the first outlet port. The grooves 39b and 390are radially spaced apart and are arranged to respectively underlie theteeth on the outer and inner rotors and to communicate with thecompartments only adjacent the roots of the teeth on the outer and innerrotors respectively. The grooves 39b and 390 extend unequal lengths fromthe end 39a and are so arranged that they respectively communicate witha compartment at the roots of the teeth on v the outer and inner rotorsat about the time the seal point S at the lead side of that compartmentmoves across the end 39a.

The other end 390! of the port 39 is angularly spaced from the end 40aof the port 40 a distance approximately equal to the spacing of the sealpoints of adjacent teeth on the inner rotor with the teeth on the outerrotor. The port 39 is preferably provided with trapping relief grooveportions 39e and 39] on the trailing end thereof which extend toward thethird port 40 and are radially spaced end thereof which extend towardthe port 39 and are also radially spaced apart to communicate with thecompartments only adjacent the roots of the teeth in the outer and innerrotors. As will be seen from FIG. 1, the grooves 40b and 40c areproportioned so as to communicate with each compartment adjacent theroots of the teeth, at about the time the seal point between the gearteeth moves across the end 4011 of the third port. The other end 4tld ofthe port 40 is angularly spaced from the adjacent end 34a of the inletport.

The percentage of gas in the liquid supplied at the inlet of the pumpwill vary in different systems and with different liquids. The relativelengths of the discharge ports are selected so that the portion of thepump displacement discharged through the port 38 exceeds .the percentageof gas in the inlet liquid. In the embodiment illustrated, the length ofport 38 is arranged so that approximately fifty percent of thedisplacement of the pump is discharged therethrough, the balance beingdischarged through the other ports 39 and 40.

The port 38 communicates through a passage 41 in the end plate 13 andthrough a conduit 42 with the reservoir 31 to return the vapor and gasand whatever liquid is discharged through the port 38 back to thereservoir. As is conventional, the reservoir 31 is vented, as by meansof a vent 44 to permit exhausting of the vapor returned to thereservoir. The other discharge ports 39 and 40 are connected throughpassages 45 and 46 in the end plate 13 and through conduit 47 and 48 toliquid distribution means (not shown) to deliver substantiallyvapor-free liquid thereto under pressure.

Somewhat improved separation of the liquid and gas can be achieved byshaping the inlet port so that at least the last portion of the fluiddrawn into the compartments at the inlet sector of the pump isintroduced adjacent the inner periphery of the compartments. For thispurpose, the outer edge 34]) of the inlet port 34 is located so that itis spaced radially inwardly from the roots of the teeth in the outerrotor, at the end 34c adjacent the first discharge port 38.

From the foregoing it is thought that the operation of the device willbe readily understood. Briefly, the liquid containing gas and occludedair enters the internal gear pump through the inlet port 34 and iscentrifugally separated due to rotation of the liquid with the inner andouter rotors 12 and 11 respectively. The relatively light gas is forcedinwardly by the. denser liquid and is discharged through the firstdischarge port 38 which is so positioned as to effect discharging of thevapor while minimizing the discharge of the vapor-free liquid. Thesubstantially vapor-free liquid is then carried in the pockets betweenthe rotors to the second discharge ports 39 and 4t) wherein it isdischarged under pressureto the liquid lines 46 and 48. As is apparent,the single internal gear pump is arranged to operate both as aliquidvapor separator and also as a boost pump to elevate the pressureon the liquid delivered to the lines 46 and 48.

A modified form of fluid separating apparatus employing a rotary vanetype Ipump is illustrated in FIGS. 46. In general, the pump housingincludes a main body 51 having a concavity 52in the upper side thereofand a bore 53 for receiving a lower shaft bearing 54. An upper end bell55 is secured to the body 51 as by fasteners56 and is sealed to the bodyby an O-ring 57. The end bell 55 has a bore 58 therein which supports anupper bearing 59. A shaft 61 is rotatably supported in the upper andlower bearings 59 and 54 and is driven by a suitable apparatusdiagrammatically indicated at 60 in FIG. 5. A shaft seal (not shown) isprovided on the upper end bell to seal the interface between the shaftand the housing. A lower plate 62 overliesthe bottom of the body 51 andthe bore 53 and is sealed thereto as by O-rings 63.

An eccentric ring 65 is disposed in the concavity 52 in the pump body 51and is held against rotation by a pin 66 which extends into the end bell55. A rotor 68 is non-rotatably connected to the shaft 61 by a key 69.

'As will be noted from FIG. 4, the outer periphery of the rotor 68 iseccentrically disposed with respect to the inner periphery of theeccentric ring 65. A plurality of vanes 71 are slidably disposed inslots .72 on the rotor and extend into a running seal with the innerwall of the eccentric ring 65, to segregate the chamber into a pluralityof compartments which rotate with the rotor and progressively increasein volume in one sector of the chamber and progressively decrease involume in another sector of the chamber. When the rotor 68 is turnedrelative to the housing in the direction indicated by the arrow in FIG.4, the compartments in that sector of the chamber located at the lefthalf of the pump will progressively increase in volume and thosecompartments located at the right hand side of the pump willprogressively decrease in volume. In the embodiment shown, the vanes 71are centrifugally actuated outwardly into a close running fit with theeccentric ring, it being understood that other conventional means suchas springs may be provided for this purpose.

Fluid is supplied to the compartments in that sector of the chamber atwhich the compartments are progressively increasing in volume through anarcuate inlet port 75. The inlet port 75 terminates short of the planethrough the axes of the rotor 68 and the eccentric ring .65 to supplyfluid to the compartments as they progressively increase in volume. Fuidis supplied to the port 75 through a passage 76 in the pump body 51 anda con-. duit 77 from a reservoir 78. The reservoir contains a fiuid 79having components such as liquid and gas which have relatively differentdensities. The combined fluid is supplied to the compartments and isrotated with the rotor so that the components of the fluid arecen'trifugally separated. The denser component of the fluid moves to azone adjacentthe outer periphery of the compartments and the lightercomponent moves to a zone adjacent the inner periphery of thecompartments. Separate outlet ports 81 and 82 are provided in thatsector of the chamber in which the compartments are progressivelydecreasing in volume to separately discharge the heavy and lightcomponents :of the fluid.

When the fluid being separated contains a gaseous component, it isadvantageous to dischargethe gaseous component first due to the tendencyof the gaseous component to expand. For this purpose, the firstdischarge or delivery port 81 is angularly spaced in the direction ofrotation of the rotor from the inlet port 75 and has the inner edge 81athereof disposed adjacent the periphery of the rotor 68 and the outeredgeSlb thereof spaced radially inwardly from the eccentric ring 65. Aswill be seen from FIG. 4, the-outer edge 81b at the end 810 of the port,approximately merges with the outer periphery of the inner rotor and isspaced inwardly from the outer wall of the compartments. The outer edge8112, at all other points therealong, is spaced inwardly from the outerwall of the compartments a minimum distance at least equal to thespacing at the .end 810 so that the volume of liquid in the compartmentsbetween the outer edge 81c and the outer walls of the compartments is atleast equal to the volume of liquid that remains in the compartments asthey move past the end 81c and out of communication with the port 81.Preferably, the outer edge 81b, at points spaced from the end 810, isspaced inwardly from the. outer peripheral walls of the compartments adistance somewhat greater than this minimal distance so as to lieclosely adjacent the outerperiphery of the inner rotor, as shown in FIG.4. The relatively lighter component of the fluid, disposed adjacent theinner periphery of the compartments, is forced outwardly through theport 81 as the compartments progressively decrease in volume. Fluid fromthe port 81 passes through a passage 82 in the pump body 51 to a conduit83. In the embodiment shown in FIG. 4, the fluid separating apparatus isarranged to separate air and vapor from liquid to dischargesubstandelivery port.

tially vapor-free liquid, and for this purpose the conduit :83 isarranged to communicate with the reservoir 78 to return the air andvapor and any liquid that is discharged. through the port 81, back tothe reservoir. A vent 84 is provided in the reservoir to vent the excessair and vapor therefrom.

The second dis-charge port '82 also communicates with the compartmentsin that sector of the chamber in which the compartments are decreasingin volume, and is angularly spaced in the direction of rotation of therotor 68 a distance at least equal to the angular spacing betweenadjacent vanes 71 On the rotor to prevent communication of the ports 81and 82 through the spaces between vanes. The relatively denser fluidwhich remains in the compartments after the lighter fluid is dischargedtherefrom through port 81, is dis-charged under pressure through seconddischarge port 82 to a passage 85 in the pump body 51 which is connectedto a delivery conduit 86.

From the foregoing it is deemed apparent that the rotary pumpingapparauts will draw the fluid into the rtating pump compartments;centrifugally separate the lighter and heavier components of the fluid,and discharge the components in different streams and under pres-sure.Thus, it is unnecessary to provide additional apparatus for feedingfluid or for withdrawing fluid from the separating apparatus.

The relative sizes of the discharge ports are related so that the changein volume in the compartments as The liquid which is removed with theair is returned to the reservoir.

While the apparatus is specifically described as used to separate liquidfrom gases, it is apparent that it is :also adapted to separate twoimmiscible liquids having diiferent densities, such as oil and water.

With the arrangements shown in FIGS. 1 and 4, the relatively lighter oilwould be discharged through the first delivery port and the heavierwater discharged through the second Moreover, a third delivery port maybe provided adjacent the outer periphery of the chamber,

to provide an airaoilwater separator.

of the fluids, said apparatus including means for effecting relativemovement of the inner and outer walls away from each other toprogressively expand the compartments as they move past an inlet zoneand for elfecting relative movement of said inner and outer walls towardeach other during a different portion of each revolution toprogressively contract the compartments as they move past a dischargezone, inlet means including at least one inlet passage communicatingwith said compartments as they move past said inlet zone cfior supplyingfluid thereto contain-ing liquid and gaseous fluids of relativelydifferent densities whereby expansion of the compart- 'ments draws thefluids to be separated into the compartments, said apparatus including afirst outlet port having one end angularly spaced in the direction ofrotation of the compartments from said inlet means and communicatingwith said compartments at the side thereof as they move past a firstsector of said discharge zone, said first outlet port terminating at itsother end intermediate the ends of the discharge zone, the radiallyouter edge of said first outlet port being spaced radially inwardly atall points therealon-g from the outer walls of said compartments, saidradially outer edge at said other end of said first outlet port beinglocated to approximately merge with the innermost periphery of saidcompartments as they move past said other end of the first outlet portwhereby the initial contraction of the compartments discharges fluidcontaining the centrifugally separated gaseous fluid from the firstoutlet port, and a second outlet port means spaced from the first outletport and communicating with said compartments as they move past a secondsector of said discharge zone whereby subsequent contraction of saidcompartments discharges the liquid fluid from the second outlet portmeans.

2. A positive displacement pump and separating apparatus comprising,means defining a plurality of expansible and contractible pumpingcompartments arranged in an annular bank and segregated from each other,said compartments having inner and outer walls, means for rotating saidcompartments about an axis paralleling the axis of said annular bank tocentrifugally separate the fluids in the compartments into radiallyinner and outer layers according to the relative density of the fluids,said apparatus including means for effecting relative movement of theinner and outer walls away from each other to progressively expand thecompartments as they move past an inlet zone and for eflecting relativemovement of said inner and outer walls toward each other during adifferent portion of each revolution to progressively contract thecompartments as they move past a discharge zone, inlet means includingat least one inlet passage communicating with said compartments as theymove past said inlet zone for supplying fluid thereto containing liquidand gaseous fluids of relatively diiferent densities whereby expansionof the compartments draws the fluids to be separated into thecompartments, said apparatus including a first outlet port having oneend angularly spaced in the direction of retation of the compartmentsfrom said inlet means and communicating with said compartments at theside thereof as they move past a first sector of said discharge zone,said first outlet port terminating at its other end intermediate theends of the discharge zone whereby a preselected volume of fluid remainsin the compartments when they move out of communication with the firstoutlet port, the radially outer edge of said first outlet port at saidother end thereof being located to approximately merge with theinnermost part of the compartments as they move past said other end ofsaid first outlet port, said radially outer edge of said first outletport being spaced radially inwardly at all points therealong from theouter Walls of the compartments as they move therepast a distance suchthat the volume of liquid in the compartments between the radially outeredge of the first outlet port and the outer walls of the compartments isno less than said preselected volume of fluid that remains in thecompartments as they move out of communication with the first outletport whereby the initial contraction of the compartments dischargesfluid contain-ing the centrifugally separated gaseous fluid from thefirst outlet port, and a second outlet port means.

partments to supply fluid to the compartments at a point inwardly of theouter peripheral wall.

4. A positivedisplacement rotary pump and separating apparatuscomprising, means including a casing having a chamber therein and arotor disposed in said chamber defining a plurality of expansible andcontractible pumping compartments arranged in an annular bank around therotor and having inner and outer walls, means for rotating said rotorabout an axis paralleling said annular bank to centrifugally separatethe fluids in the compartments, said rotor being located eccentricallyin said chamber whereby the inner and outer walls of the compartmentsmove away from each other during one portion of each revolution toprogressively expand the compartments as they move past an inlet zoneand the inner and outer walls move toward each other during adifli'erent portion of each revolution to progressively contract thecompartments as they move past a discharge zone, inlet means includingat least one inlet passage communicating with said compartments as theymove past said inlet zone for supplying fluid thereto containing liquidand gaseous fluids of relatively diflerent densities whereby expansionof the compartments draws the fluids to be separated into thecompartments, the casing including a first outlet port having one endangularly spaced in the direction of rotation of the compartments fromsaid inlet means and communicating with said compartments at the sidethereof as they move past a first sector of said discharge zone, saidfirst outlet port terminating at its other end intermediate the ends ofthe discharge zone whereby a preselected volume of fluid remains in thecompartments when they move out of communication with said first outletport, the radially outer edge of said first outlet port at said otherend thereof being located to approximately merge with the innermost partof the compartments as they move past said other end of said firstoutlet port, said radially outer edge of said first outlet port beingspaced radially inwardly at all points therealong from the outer -wallsof the compartments as they move therepast a distance such that thevolume of fluid in the compartments between the radially outer edge ofthe first outlet port and the outer walls of the compartments is no lessthan said preselected volume that remains in the compartments as theymove out of communication with said first outlet port [whereby theinitial contraction of the compartments discharges fluid containing thecentrifiugally separated gaseous fluid from the first outlet port, and asecond outlet port means spaced from the first outlet port andcommunicating with said compartments as they move past a second sectorof said discharge zone whereby subsequent contraction of saidcompartments discharges the liquid fluid from the second outlet portmeans.

5. A positive displacement rotary pump and separating apparatuscomprising, a casing defining a chamber, inner and outer eccentricallyrelated rotors having interengaging teeth defining a plurality ofsegregated pumping compartments therebetween arranged in an annularbank, means for rotating said rotors about relatively eccentric axeswhereby the compartments progressively expand during one portion of eachrevolution as they move past an inlet zone and progressively contractduring a different portion of each revolution as they move past adischarge zone, inlet means including at least one inlet passagecommunicating with said compartments as they move past said inlet zonefor supplying fluid thereto containing liquid and gaseous fluids ofrelatively different densities, whereby expansion of the compartmentsdraws the fluids to be separated into the compartments, the casingincluding a first outlet port having one end angularly spaced in thedirection of rotation of the compartments from said inlet means andcommunicating with said compartments at the side thereof as they movepast a first sector of said discharge zone, said first outlet porttenminating at its other end intermediate the ends of the discharge Zonewhereby a preselected volume of fluid remains in the compartments whenthey move out of communioation with said first outlet Port, the radiallyouter edge of said first outlet port being shaped to approximately mergewith the roots of the teeth on the inner rotor at said other end of saidfirst outlet port, said radially outer edge being spaced radiallyinwardly from the roots of the teeth on the outer rotor at all pointstherealong a distance such that the volume of fluid in the compartmentsbetween the radially outer edge of the first outlet port and the teethon the outer rotor is no less than said preselected volume that remainsin the compartments when they move out of communication with said firstoutlet port whereby the initial contraction of the compartmentsdischarges fluid containing the centritug-ally separated gaseous fluidfrom the first outlet port, and a second outlet port means spaced (fromthe first outlet port and communicating with said compartments as theymove past a second sector of said discharge zone whereby subsequentcontraction of said compartments dischargesthe liquid fluid from thesecond outlet port means.

6. The combination of claim 5 wherein the radially outer edge of saidinlet port is spaced radially inwardly .from the roots of the teeth onthe outer rotor at the end adjacent said first outlet port to supplyfluid to the compartments at a point inwardly of the outer periphery ofthe compartments.

7. A positive displacement pump and separating apparatus comprising,means defining a plurality of expansible and contractible pumpingcompartments arranged in an annular bank and segregated from each other,said compartments having inner and outer walls, means for rotating saidcompartments about an axis paralleling the axis of said annular bank tocentrifugally separate the fluids in the compartments into radiallyinner and outer layers according to the relative density of the fluids,said apparatus including means for effecting relative movement of theinner and outer Walls away from each other to progressively expand thecompartments as they move past an inlet zone and for effecting relativemovement of said inner and outer walls toward each other during adifferent portion of each revolution to progressively contract thecompartments as they move past a discharge zone, inlet means includingat least one inlet passage communicating with said compartments as theymove past said inlet zone for supplying fluid thereto containing liquidand gaseous fluids of relatively different densitives whereby expansionof the compartments draws the fluids tobe separated into thecompartments, said apparatus including a first outlet port having oneend angularly spaced in the direction of rotation of the compartmentsfrom said inlet means and communicating with said compartments at theside thereof as they move past -a first sector of said discharge zone,said first outlet port terminating at its other end intermediate theends of the discharge zone whereby-the inner walls of the compartmentsare spaced radially inwardly a preselected distance from the outer wallsof the compartments as the compartments move out of communication withsaid first outlet port, the radially outer edge of said first outletportat said other end thereof being spaced radially inwardly from theouter walls of the compartments ,a distance slightly less than saidpreselected distance, and said radially outer edge of said first outletport at all other points therealong being spaced inwardly from the outerwalls of the compartments a distance at least as great as the radialspacing at said other end whereby initial contraction of thecompartments discharges fluid containing the centrifugally separatedgaseous fluid through the first outlet port, and a second outlet portmeans spaced from the first outlet port and communicating with saidcompartments as they move past a second sector of said discharge zonewhereby subsequent contraction of said compartments discharges liquidfluid from the second outlet port means.

8. A positive displacement rotary pump and separating apparatuscomprising, a casing defining a chamber having a peripheral wall, arotor mounted in said chamber for rotation about an axis eccentric tosaid peripheral wall, a plurality of vanes rotatable with the rotor andengaging the peripheral wall of the casing to define a plurality ofsegregated pumping compartments which progressively expand during oneportion of each revolution as the compartments move past an inlet zoneand progressively contract during another portion of each revolution asthe compartments move past a discharge zone, inlet means including atleast one inlet passage communicating with the compartments as they movepast said inlet zone for supplying fluid thereto containing liquid andgaseous fluids of relatively difiFerent densities whereby expansion ofthe compartments draws the fluids to be separated into the compartments,the casing including a first outlet port having one end communicatingwith said compartments at the side thereof as they move past a firstsector of said discharge zone, said first outlet port terminating at itsother end intermediate the ends of the discharge zone whereby theperiphery of the rotor is spaced a preselected distance from theperipheral wall of the casing as the compartments move out ofcommunication with the first outlet port, the radially outer edge of thefirst outlet port at said other end thereof being spaced radiallyinwardly from the peripheral wall of the casing a distance slightly lessthan said preselected distance, and said radially outer edge of saidfirst outlet port at all other points therealong being spaced inwardlyfrom the peripheral wall of the casing a distance at least as great asthe radial spacing at said other end whereby initial contraction of thecompartments discharges fluid containing the centrifugally separatedgaseous fluid through the first outlet port, and a second outlet portmeans spaced from the first outlet port and communicating with thecompartments as they move past a second sector of said discharge zonewhereby subsequent contraction of said compartments discharges liquidfluid from the second outlet port means.

9. A positive displacement rotary pump and separating apparatuscomprising, a casing defining a chamber,

inner and outer eccentrically related rotors having interengaging teethdefining a plurality of segregated pumping compartments therebetweenarranged in an annular bank, means for rotating said rotors aboutrelatively eccentric axes whereby the compartments progressively expandduring one portion of each revolution as they move past an inlet zoneand progressively contract during a different portion of each revolutionas they move past a discharge zone, inlet means including at least oneinlet passage communicating with said compartments as they move pastsaid inlet zone for supplying fluid thereto containing liquid andgaseous fluids of relatively diiferent densities, whereby expansion ofthe compartments draws the fluids to be separated into the compartments,the casing including a first outlet port having one end angularly spacedin the direction of rotation of the compartments from said inlet meansand communicating with said compartments at the side thereof as theymove past a first sector of said discharge zone, said first outlet portterminating at its other end intermediate the ends of the discharge zonewhereby a preselected volume of fluid remains in the compartments whenthey move out of communication 'with said first outlet port, theradially outer edge of said first outlet port being shaped toapproximately merge with the roots of the teeth on the inner rotor atsaid other end of said first outlet port, said radially outer edge beingspaced radially inwardly from the roots of the teeth on the outer rotorat all points therealong a distance such that the volume of fluid in thecompartments between the radially outer edge of the first outlet portand the teeth on the outer rotor is no less than said preselected volumethat remains in the compartments when they move out of communicationwith said first outlet port whereby the initial contraction of thecompartments discharges fluid containing the centrifugally separatedgaseous fluid 'from the first outlet port, and at least one secondoutlet port communicating with said compartments as they move past asecond sector of said discharge zone, said second outlet port having oneend extending crosswise of the compartments as they move therepast andangularly spaced from said other end of said first outlet port, saidsecond outlet port having a trapping relief groove portion in saidcasing extending from said one end of said second port toward said firstoutlet port and located to communicate with the roots of the teeth inone of the gears.

10. A positive displacement rotary pump and separating apparatuscomprising, a casing defining a chamber, inner and outer eccentricallyrelated rotors having interengaging teeth defining a plurality ofsegregated pumping compartments therebetween arranged in an annularbank, means for rotating said rotors about relatively eccentric axeswhereby the compartments progressively expand during one portion of eachrevolution as they move past an inlet zone and progressively contractduring a diflerent portion of each revolution as they move past adischarge zone, inlet means including at least one inlet passagecommunicating with said compartments as they move past said inlet zonefor supplying fluid thereto containing liquid and gaseous fluids ofrelatively different densities, whereby expansion of the compartmentsdraws the fluids to be separated into the compartments, the casingincluding a first outlet port having one end angularly spaced in thedirection of rotation of the compartments from said inlet means andcommunicating with said compartments at the side thereof as they movepast a first sector of said discharge zone, said first outlet portterminating at its other end intermediate the ends of the discharge zonewhereby a preselected volume of fluid remains in the compartments whenthey move out of communication with said first outlet port, the radiallyouter edge of said first outlet port being shaped to approximatelyrnerge with the roots of the teeth on the inner rotor at said other endof said first outlet port, said radially outer edge being spacedradially inwardly from the roots of the teeth on the outer rotor at allpoints therealong a distance such that the volume of fluid in thecompartments between the radially outer edge of the first outlet portand the teeth on the outer rotor is no less than said preselected volumethat remains in the compartments when they move out of communicationwith said first outlet port whereby the initial contraction of thecompartments discharges fluid containing the centrifugally separatedgaseous fluid from the first outlet port, at least one second outletport communicating with said compartments as they move past a secondsector of said discharge zone, said second outlet port having one endextending cross-wise of the compartments as they move therepast andangularly spaced from said other end of said first outlet port, saidsecond outlet port having radially spaced inner and outer trappingrelief groove portions in said casing extending from said one end ofsaid second outlet port toward said other end of said first outlet portand positioned to respectively underlie the teeth on the inner and outerrotors and to communicate with a compartment adjacent the roots of theteeth on the inner and outer rotors when the seal point of the teeth onthe inner and outer rotors moves across said one end of said secondoutlet port.

11. A positive displacement rotary pump and separating apparatuscomprising, a casing defining a chamber, inner and outer eccentricallyrelated rotors having intereng-aging teeth defining a plurality ofsegregated pumping compartments therebetween arranged in an annularbank, means for rotating said rotors about relative-1y eccentric axeswhereby the compartments progressively expand during one portion of eachrevolution as they move past an inlet zone and progressively contractduring a 'diifercnt portion of each revolution as they move past adischarge zone, inlet means including at least one inlet passagecommunicating with said compartments as they move past said inlet zonefor supplying fluid thereto containing liquid and gaseous fluids ofrelatively different densities, whereby expansion of the compartmentsdraws the fluids to be separated into the compartments, the casingincluding a first outlet port having one end angularly spaced in thedirection of rotation of the compartments from said inlet meansandcommunicating with said compartments at the side thereof as they movepast a first sector of said discharge zone, said first outlet portterminating at its other end intermediate the ends of the discharge zonewhereby a preselected volume of fluid remains in the compartments whenthey move out of communication with said first outlet port, the radiallyouter edge of said first outlet port being shaped to approximately mergewith the roots of the teeth on the inner rotor at said other end of saidfirst outlet port, said radially outer edge being spaced radiallyinwardly from the roots of the teeth on the outer rotor at all pointstherealong a distance such that the volume of fluid in the compartmentsbetween the radially outer edge of the first outlet port and the teethon the outer rotor is no less than said preselected volume that remainsin the compartments when they move out of communication with said firstoutlet port whereby the initial contraction of the compartmentsdischarges fluid containing the centrifugally separated gaseous fluidfrom the first outlet port, second and third outlet ports communicatingwith said compartments as they move past a second sector of saiddischarge zone, said second outlet port having first and second endsangularly spaced from said first and third outlet ports, respectively,said second port having trapping relief groove portions extending fromthe first and second ends thereof toward said first and third outletports and located to communicate with the roots of the teeth in one ofthe gears.

12. A positive displacement pump comprising, a casing defining achamber, inner and outer eccentrically related rotors havinginterengaging teeth defining a plurality of segregated pumpingcompartments therebetween arranged in an annular bank, means forrotating said rotors about relatively eccentric axes whereby thecompartments progressively expand during one portion of each revolutionas they move past an inlet zone and progressively contract during adiiferent portion of each revolution as they move past a discharge zone,in-let means including at least one inlet passage communicating withsaid compartments as they move past said inlet zone for supplying fluidthereto, first and second outlet ports communicating with saidcompartments at the side thereof as they move past said discharge zone,said first outlet port having one end angularly spaced from said inletport and the other end angularly spaced from one end of said secondoutlet port, said second outlet port having radially spaced inner andouter trapping relief groove portions extending from said one end towardsaid first port and positioned to respectively underlie the teeth on theinner and outer rotors and to communicate with the compartments adjacentthe roots of the teeth on the inner and outer rotors when the seal pointbetween the teeth on the inner and outer rotors moves across said oneend of said second outletport.

13. A positive displacement pump comprising, a casing defining achamber, inner and outer eccentrically related rotors havinginterengaging teeth defining a plurality of segregated pumpingcompartments therebetween arranged in an annular bank, means forrotating said rotors about relatively eccentric axes whereby thecompartments progressively expand during one portion of each revolutionas they move past an inlet zone and progressively contract during adifferent portion of each revolution as they move past a discharge zone,inlet means including at least one inlet passage communicating with saidcompartments as they move past said inlet zone for supplying fluidthereto, first and second outlet ports communicating with saidcompartments at the side thereof as they move past said discharge zone,said first outlet port having one end angularly spaced from said inletp011 and the other portion angularly spaced from one end of said secondoutlet port, said other end portion of said first outlet port beinglocated to underlie the teeth on the inner rotor and communicate withthe compartments only adjacent the roots of the teeth on the innerrotor, said second outlet port having a trapping relief groove portionextending from said one end of said second outlet port toward said firstoutlet port and spaced radially outwardly from said one end portion ofsaid first port to underlie the teeth on the outer rotor an tocommunicate with the compartments only adjacent the roots of the teethon the outer rotor when the seal point between the teeth on the innerand outer rotors moves across said one end of said second outlet port.

14. In combination with a liquid receptacle, a positive displacementpump apparatus for pumping fluid from the receptacle and for returningthe lighter centrifugally separated fluids to the receptacle comprising,means defining a plurality of expansible and contractible pumpingcompartments arranged in an annular bank and segregated from each other,said compartments having inner and outer walls, means for rotating saidcompartments about an axis paralleling the axis of said annular bank tocentrifugally separate the fluids in the compartments, said apparatusincluding means for effecting relative movement of the inner and outerwalls away from each other during one portion of each revolution toprogressively expand the compartments as they move past an inlet zoneand for effecting relative movement of the inner and outer walls of thecompartments toward each other during a different portion of eachrevolution to progressively contract the compartments as they move pasta discharge zone, inlet means communicating with said receptacle andincluding at least one inlet port communicating with said compartmentsas they move past the inlet zone whereby expansion of the compartmentsdraws fluid from the receptacle into the compartments, a first gasoutlet port angularly spaced in the direction of rotation of thecompartments from said inlet port and positioned radially inwardly fromthe outer walls of the compartments and closely adjacent the inner wallsof the compartments to communicate with the compartments as they movepast a first sector of said discharge zone whereby the intialcontraction of the compartments forces the lighter centrifugallyseparated fluid from adjacent the inner periphery of the compartmentsthrough the first outlet port, passage means connecting the first outletport with said receptacle to vent the lighter centrifugally separatedfluid from the outlet port to the receptacle, and a second outlet portspaced from the first outlet port and communicating with saidcompartments as they move past a second sector of said discharge zonewhereby subsequent contraction of said compartments discharges theliquid fluid from the second outlet port.

References Cited by the Examiner UNITED STATES PATENTS 1,345,895 8/1920Seguin 103-113 1,902,315 3/1933 Vogt 103-126 2,053,919 9/1936 Pigott103126 2,217,211 10/1940 Brady 103-113 2,416,987 3/ 1947 Fleischer103-426 2,417,701 3/1947 Parsons 103126 2,539,044 1/ 1951 Walsh 103--1262,732,802 1/1956 Eames 103126 3,137,234 6/1964 Mosbacher 103-2 MARKNEWMAN, Primary Examiner.

SAMUEL LEVINE, Examiner.

W. L. FREEH, Assistant Examiner.

1. A POSITIVE DISPLACEMENT PUMP AND SEPARATING APPARATUS COMPRISING,MEANS DEFINING A PLURALITY OF EXPANSIBLE AND CONTRACTIBLE PUMPINGCOMPARTMENTS ARRANGED IN AN ANNULAR BANK AND SEGREGATED FROM EACH OTHER,SAID COMPARTMENTS HAVING INNER AND OUTER WALLS, MEANS FOR ROTATING SAIDCOMPARTMENTS ABOUT AN AXIS PARALLELING THE AXIS OF SAID ANNULAR BANK TOCENTRIFUGALLY SEPARATE THE FLUIDS IN THE COMPARTMENTS INTO RADIALLYINNER AND OUTER LAYERS ACCORDING TO THE RELATIVE DENSITY OF THE FLUIDS,SAID APPARATUS INCLUDING MEANS FOR EFFECTING RELATIVE MOVEMENT OF THEINNER AND OUTER WALLS AWAY FROM EACH OTHER TO PROGRESSIVELY EXPAND THECOMPARTMENTS AS THEY MOVE PAST AN INLET ZONE AND FOR EFFECTING RELATIVEMOVEMENT OF SAID INNER AND OUTER WALLS TOWARD EACH OTHER DURING ADIFFERENT PORTION OF EACH REVOLUTION TO PROGRESSIVELY CONTRACT THECOMPARTMENTS AS THEY MOVE PAST A DISCHARGE ZONE, INLET MEANS INCLUDINGAT LEAST ONE INLET PASSAGE COMMUNICATING WITH SAID COMPARTMENTS AS THEYMOVE PAST SAID INLET ZONE FOR SUPPLYING FLUID THERETO CONTAINING LIQUIDAND GASEOUS FLUIDS OF RELATIVELY DIFFERENT DENSITIES WHEREBY EXPANSIONOF THE COMPARTMENTS DRAWS THE FLUIDS TO BE SEPARATED INTO THECOMPARTMENTS, SAID APPARATUS INCLUDING A FIRST OUTLET PORT